In recent years, spray and/or aerosol-type dispensers have received attention for their use in dispensing liquids, particularly medicaments. One persistent problem in designing spray and/or aerosol dispensers for dispensing medicaments is preventing contamination of the medicament which can occur when the medicament that has been exposed to ambient air returns and/or remains in the aerosol outlet channel, e.g., within the aerosol nozzle. One solution to this problem is to simply add preservatives to the medicament being dispensed, thereby preventing bacterial growth. However, this solution has obvious disadvantages, e.g., added costs and toxicity of the preservatives. In order to prevent bacterial growth in medicament which does not contain preservatives while allowing dispensation of multiple doses of the medicament, the aerosol nozzle must prevent medicament that has been previously exposed to ambient air from being sucked back into the aerosol outlet channel.
Another problem in designing spray and/or aerosol dispenser for dispensing medicaments is minimizing the number of components which constitute the spray/aerosol dispenser. As the number of components increases, the difficulty and cost of mass production increases.
Accordingly, it is an object of the present invention to provide an outlet nozzle or tip mechanism for dispensing liquid from a pump-type dispenser in aerosol or spray form, which nozzle or tip mechanism is adapted for combination with the pump-type dispenser without the need for additional components for, or modification of, the pump-type dispenser for facilitating the combination.
It is another object of the present invention to provide an outlet nozzle for an aerosol dispenser, which nozzle ensures one-way movement of liquid through the nozzle.
It is yet another object of the present invention to provide a method of dispensing liquid through an outlet nozzle for an aerosol dispenser, which method ensures one-way movement of liquid through the nozzle.
It is yet another object of the present invention to provide an outlet nozzle for an aerosol dispenser, which nozzle has a substantially zero "dead volume" in which liquid that has been exposed to ambient air can remain, i.e., the liquid is completely released once it passes through the outlet nozzle, or the combined effect of the surface tensions of the liquid and the surrounding outlet nozzle forces any remaining liquid out of, and away from, the outlet portion.
It is yet another object of the present invention to provide a method of ensuring that no liquid which has been exposed to ambient air returns to the interior portion of the nozzle of an aerosol dispenser.
It is yet another object of the present invention to provide an aerosol dispenser with a one-way nozzle, which dispenser minimizes the number of parts for manufacturing.
It is yet another object of the present invention to provide an aerosol dispenser having a plurality of valve mechanisms in the fluid communication path between the liquid reservoir and the outlet nozzle to ensure minimization of contact between the content of the liquid reservoir and liquid which may have been previously exposed to ambient air.
It is another object of the present invention to provide an outlet nozzle for an aerosol dispenser, which nozzle is adapted to generate an aerosol-type discharge by means of elastic, radial deformation along the circumference of the nozzle which provides an integral spring, while substantially maintaining the physical profile in the direction of the longitudinal axis of the nozzle.
It is another object of the present invention to provide an aerosol-type dispenser which does not require propellants such as CFCs, the release of which is harmful to the ozone layer, or the release pressure of which propellant is temperature dependent, thereby creating variations in dispensed dosages.
It is another object of the present invention to provide a pump-and-nozzle system for generating an aerosol-type discharge via a swirling chamber by means of an integral spring effect achieved by elastic, radial deformation along the circumference of the nozzle, which aerosol-type discharge is achieved with a minimum of "head loss."